TOPIC:

I still need to cross drill the differential shafts... The printed plastic hole doesn't work good enough for the centering of the cross drilling. I discuss with my friend Dadio, and he suggested to use a piece of rod drilled in the center section to guide the drill bit (super easy to do with a lathe, but I do not have one). But first I needed a more precise drill press... I ordered an Arrowmax mini drill during the black friday, and it arrived promptly... But I must say that I'm a bit disappointed by the platform : the drilling bit is not centered in the hole of the platform (seems like amateurish work - this version has a piece to allow orientation at angle, and I suppose the offset linked to that part was never taken into account - I would have expected something more toroughly thought)...
Once you know it, at the end it is just question of measuring to do the proper centering... Then I built over the idea and decided to use ball bearings...


Now, I just have to find a better drill bit. The one I use currently is already dead, but at least it allowed me to confirm the centering is working as expected. I'll get proper drilling bits in 2mm and I'll expect this to be a long drilling exercise due to the limited rotation speed...

The dremel workstation is crap, the arrowmax mini drill too slow... I took a different approach considering that the proper guiding would be enough to make proper holes with just the normal drill if I pay attention to make it right... Two drill bits broken later, I have my 4 shafts for the diff.


What remains to deal for the metal parts are :
- 4 pins for the diff (2mm) - just cut, this would be easy
- 1 bevel gears axis (3mm) - just cut, this would be easy
- 8 suspension shafts - cuts and flats, this would be again an easy one to deal with

Today, I cut the last shafts I needed for the Zerda (again a template set in 3D print to set the cuts and flat areas). I intend to fix the shafts using grub screws set in the arms.


I need to work out a template to drill the arms, and once this will be done, assembly can start...

All shafts done and ready... And, yes, there was no lathe involved in any of those parts at my end : just ideas and very basic tools...

I've chosen to fix the suspension shafts with a grub screw positioned in the arms... But this require precise drilling in the arms. Nylon is easy to drill, and I have now some precision tool...
I used a printed jig to drill precisely. Beside this, I will prepare an amended version of the arms specifically designed for this...


And as we need to carefully set this on both side of the arms, and there is two different lengths, that makes two jigs.


Maybe I need to do a full inventory of the screws and nuts I need for the build now...

Yesterday, I printed the pulley cover in Translucent ABS, and I decided to try something different... I used PETG as support interface material...


The PETG was mostly removed...


To remove the last bit i used a grinding tool... It's not perfect, but much better than what the previous ones I printed...


I noticed that I messed up my order for GT2 pulley. Instead of ordering a 4mm bore for the inside pulley, I ordered a 5mm bore... But I have easy solutions : a tube, some plumbing basic tool to cut it, and a hole drilled in the right place...


and : voilà!




Then I used silicon tubing to do the required sleeves to center the pulley and rollers. It might require some adjustment, but it would be super easy to cut new ones...

Time to play with colors again... Rit Dye Orange Apricot


If ever you use this dye tone, be careful, the bubles are giving a clearer tone to the parts compared to what it is in reality... As a result it is a bit too dark compared to what I wanted initially... But it will be fine and different...

Problem of the day : king pins.


I know that my friend Dadio would say it is easy to do with a lathe (i'm sure it is, by the way), but I do not have a lathe...
As usual i'm going to work aorund this with printed parts, a file, a few screws ball bearing and a drill. Starting point will be a 3.5mm screw. I already printed the parts, the 3.5mm diameter screws I'll use as a starting point should come tomorrow. 

It worked, mostly...


A M3.5 screw is not a perfect starting point as the root of the thread is under 3mm diameter. But this will do it...

Happy New Year and best wishes to everyone!

This morning I had my first success of 2025, I hope there will be more

The build of this Zerda starts by the differentials. Not a single original part is present on those pictures and was used. Differential internals are optima rerelease diff internals and custom made shafts. I had to drill and cut a new shaft as the second one I did had a slightly off center hole, and the pin was not fitting in the bevel gear. There is ball bearing cages added on my modded diff case.






Good news : they work perfectly. Bad news, I do not have enough 9x17x5 ball bearings to assemble the transmission fully today. Ordered some. They should arrive Friday or Saturday.

I printed the rollers used to make the belt path and the tension in TPU.


Next I assembled the carriers... Again, no original parts. I'll use some HBX wheel shafts, and double bearings to reduce the play.




Again, perfect fit... I'll continue the build soon, but I need the diff ball bearings first...